The £660-a-day treatment, sofosbuvir, was approved on the grounds that it is a cost effective way of treating patients who would go on to require high costly intervention – one in three Hep-C sufferers develops liver cirrhosis and require a liver transplant at a cost of around £50,000.

But NHS England is understood to have delayed the cost because it will cost £1bn for every 20,000 who require treatment, and Charles Gore, chief of executive of the Hepatitis C Trust,said: ‘It is undoubtedly a high cost. The unfortunate thing is there are an awful lot of people who need it.’

The guidance states that during unexpected surges in A&E attendance staff should be drafted in from other wards and departments, and an on-call rota should be used to ensure nursing levels don’t drop too low.

Andy Burnham, the shadow health secretary, said: ‘This clear guidance is welcome, but many hospitals are nowhere near this level. The Government needs to set out how it will meet this plan.’

Research, published in Current Biology, treated undergraduates with a stress hormone blocking drug and noted a significant increase in how much pain they believed a stranger - whose hand was plunged into cold water - was in.

Dr Jeffrey Mogil, study author and neuroscientist from McGill University in Montreal, Canada, said his team’s findings suggest that the stress system in the brain can have a ‘veto’ on our empathy system.